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Are they Really That Tall?

Student Worksheet 2




Name __________________________      Period_______      Date_______________



This activity will focus analysis of two variable statistics. This is called bivariate data. You will use the NBA stats that you have previously downloaded. You will notice on these sheets, there are many statistics listed for the team members. If you need an interpretation of the abbreviations go back to the NBA website.

Two-variable statistics often asks the question, "Is there a relationship between the two variables?" One does not have to cause the other; there can just be an association between them. Think of two variables that you would like to analyze. For example, is there a relationship between how many games played and how many rebounds a player has? This is a fairly easy one to answer. You are not limited to just the stats from the team stats page. You can also find individual statistics about a player by returning to the website, www.nba.com.

Does the number of years a player is in the NBA have any correlation (relationship) to the number of points scored? You would need to select a player and find the appropriate statistics.

  1. Write your question. _____________________________________________________________________

  2. Identify the two variables. __________________________________________

  3. The variable that you choose for the horizontal axis is called the independent (or explanatory) variable and the variable that you choose for the vertical axis is the dependent (or response) variable.

    Independent variable ___________________Dependent variable __________________

  4. Using technology, enter the data into L1 and L2. Make sure that you have the same number of values in each list or you will get an invalid dimension error.

  5. Choose STAT PLOT to select the scatterplot and graph the data.

    When you press ZoomStat, the scatterplot will be shown.
    Press 2nd y= for this screen choice.\ Select the 1st plot, which are the scatterplot and the appropriate lists. ZoomStat will fit the window to the data that is in the two lists.

  6. Describe the scatterplot. You can go to the vocabulary link to see specific terms used for describing data.**** ______________________________________________________________________________

  7. Does there appear to be a correlation between the two variables that you selected? ________ Why or why not? __________________________________________________________________________________

  8. Which algebraic model do you think would best fit this data? Think about a linear model, quadratic model, and exponential model as a few. ______________________________________

  9. Why did you choose the above model? ______________________________________________________

    Fit the data to the model that you have chosen. Under the STAT-CALC menu you will find the entire algebraic model to choose from. If you want the model drawn over the scatterplot, enter the following keystrokes: The example given is for a linear model with data in L1 and L2.

    Press the STAT key. Arrow over to CALC. Choose #4, Linear Regression, the type in the List names with commas after each one. Press VARS so that you can have the equation pasted into Y1.
    When you press GRAPH, you should see your algebraic model and the scatterplot.
    Arrow over to Y-VARS. Choose the place where you want the equation pasted. Press ENTER and the coefficients for the equation will be shown as well as "r" and "r2". For information about "r" and "r2" see the vocabulary link. If your display does not give you "r" and "r2", you will need to turn your DIAGNOSTICS ON.
    Press 2nd 0 to find the Catalog. The "A" in the upper right hand part of the screen is letting you know that you are in ALPHA mode. Press the key that has the letter "D". Arrow down to Diagnostic On and press ENTER twice. Now, re-run the regression again and you will see the complete regression information.

  10. Write the equation of your linear regression. _____________________________

  11. State what each of the variables represents: x __________ y __________

  12. What is the meaning of the slope of your line in this example? ____________________________________

  13. What is the meaning of the y-intercept in this example? __________________________________________

  14. The "r" value for your regression is ________. If this value is close to 1 or -1, it shows a strong correlation between the two variables. Make a statement about your "r" value. ________________________________

  15. Summarize your findings about the relationship between the two variables that you have chosen to compare. Use complete sentences. __________________________________________________________________________________________________


The Integrating Technology into Math Instruction webpages project is partially funded by a grant from The Boeing Company. Integrating Technology into Math Instruction is a project of +PLUS+ and is displayed on the Los Angeles Educational Partnership Learning Exchange. +PLUS+ is an initiative of the Los Angeles Educational Partnership.
Updated June 2000